Apparatus for the manufacture of lenses.



M BENTZON. APPARATUS FOR THE MANUFACTURE OF LENSES.

APPLICATION FILED JULY 28,1911.

Patentd Sept. 9, 1913.

2 SHEETS-SHEET 1.

Wit/masses.-

M. BENTZON. APPARATUS FOR THE MANUFACTURE OF LENSES.

APPLICATION FILED JULY 28,1911.

Patented Sept. 9, 1913.

2 SHEETSSHEET 2.

V6. q &

Dix KMd hmM zinesses;

subject of the King of Great Britain. re

,m ccm BENTZUN, or Lennon, ENGLAND.

Arrana'rns Eon *Tnn manor g o'ronn be Lenses. j.

Application filed July 28, 1911. Serial No. 641,069.

To all whom it may concern Be it known that I, MALcotnr Bnxrzox a ing at 188 Strand, London. England. have ini ented new and useful improvements in Apparatus for the Manufacture of Lenses. of which the following is a specification.

My invention relates to apparatus for grinding and polishing bi-tocal and other lenses and to that class of apparatus harming the subject of pending application Serial Bio.

ISQSflOO of which I am one ot the inventors and wherein the grinding tools are capable of os illator} motion on the driving spindles.

The specification of the said pending application describes inter 07in an apparatus wherein a series of grinding and polisning toolig is arranged to operate simultaneously on'the ouiter curvature of the lens. the tools in one arrangement being carried by sepai'ate head's and in another arrangement carried on a 'connnon driving shaft. In this latter arrangement, however, the said tools not'only rotate on their wn axes hut'also revolve around the axis of the lens and this dual novenient of the grinding tools presents diiiiculties in connection with the construction and operation which very much detract from the practical utility of the apparatus, furthermore with this latter arrangement all the tools rotateiin the same direc tion. whereas, in practice, it is advisable that some of the tools should'rotate in one direction and some in'the other.

Now, according toniy presentinvention. l mount the spindles for the several grinding tools in a fixed head so that the said tools have only a motion of rotation on their axes, the rotation of the lens holder beneath toe grinding tools serving to bring all the par s of the lens under the action of the tools.

In a suitable arrangement for carrying outniy invention, the spindles are mounted in hearings in a fixed head, springs being arranged in Connection with the spindles for enablin thcin'to yield to a certain extent in a longitudinal direction for the purpose of causing the tools to act upon thesurr'ace being ground with spring pressure. The

said bearings may beadapt-ed to be adjusted {It angle 'soas to enable them to be tired in P i n-normal to the surface being ground;

l The spindles may be driven in any suit- Sp'ecification of Lctter s latent V able manner. but I find it advantageous to drive them. independently, through the medium of flexibleshatts from the several wheels of a' chain of gear wheels, to ione of which rota r1 driving motion is i1nparted,this arrangement of flexible shafts and gearing allowing of the necessary longitudinal movenient of the spindles under the action of the springs, and also providing for rotating some of them in one direction and some in the other direction.

Where it is desired to provide for varying the distance between the centers of the grinding tools according to the diameter of the grinding tools used, or of the lens heing ground. I can arrange the spindles in slots in the head. and provide a series of teinplcts having notches or slots corresponding with the varving positions in which it may be desired to place the spindles and which ternplets can he applied to the head to embrace the spindles. and to retain them in; their" proper axial positions. v

The arm which supports the head upon the base may advantageously have a sliding adjustable saddle upon carrying the table upon which the lenses are fixed fol-grinding'. and which table. as hereinheforo stated. is adapted to be. rotated beneath the grind ing tools. I i

' nahle inv invention to be fully underwill describe the same by reference to me accompanying drawing. in which Figure l is a sectional side elevation'ot Ill-f. improved apparatus. Fig. Zis a plan with the cover removed. Fig. 3 is a section on the line 3 -23. l. 2-3 is a detail elevation of the tool operating spindles and their carrying arms.

Fig. 4-

asection on the line l.l- Fig. 1 looking in the direction of the arrow in the said figure. and Fig. is also a section on the line il hut lookingin the reverse direction to that of the arrow.

a indicates the pillar or standard of'thc machine. which. as hown. is of triangular shape. in cross section and fixed at its lower end to a base Z). while at its upper end it. carries a plate to wl 'ch the head 1/ cartthe grinding spindles is fixed. I

As shown, this head (1 coin n-iscs top and bottom plates (2. with an intermediate ring or shell 7" which clamped hctween the. plates 6, e and held in position hvineans of screws 9, g which pass through the plate 0,

and serve also for drawing the head up against the underside of the said plate to secure it in-place. v

' h, h are arms (one. of which'is shown detached in Fig. 3 pivoted at h to the plates 0,0 as indicated in Figs. 3 and 4, and carrying at their free ends hearings in which the spindles 2', i for operating the grinding tools are mounted. Each of the spindles as shown, has upon it a collar j, between which and the upper side of an openin L in the arm h is located a spring 7' which allows of the longitudinal movement of the spindle in the bearing. The upper ends of the spindles i, which project above the plate 6, are adapted to' have connected to them means for driving them; as shown in the drawing each spindle has connected to it one end of a flexible shaft Z, the other end of which is secured tothe boss ofa gear-wheel m.

The several gear-wheels m, m, which are all of the samediameter, are geared togetherand receive their motion through a spindle 71. attached to one of them so that they will connection with grindin tools of the kind all rotate simultaneously (some in one direction and some .in the other) at the same speed and transmit their movement to the several spindles 2', The lower ends of the spindles i, i'are provided with carriers 71, i or adapted in any other suitable manner for described in the speci cation before referred to.

The plates 6, e have formed in them curved slots 0 6 through which the spindles i, 2 pass so as-to allow of the spindles i, z'being arranged radially nearer to or farther from the center of the head, as desired,

and the position of the said spindles is regulated by the employment of a templet 0 having formed upon it a series of hooks designed to engage with the spindles in a manner which will be readily understood by ref-. erence to Figs. 3 and 4. This templet isapplied to a central pin 19 passing through the head, the hook portions being passed between the carriers, and the templet then turned to. engage the hooks with the spindles.

To allow for locking the templet in position the central pin 39 is mounted on an eccentric 9 carried by a spindle (7 the rotation of which serves to move the said pin longitudinally, the central hole in the templet being made large enough to pass over an adjustable hot 72 on the lower end of the said spindle 9. To hold'the templet on the pin 79 above the nut 79. I provide a loose slotted collar r, which, when the said pin is in its lowest position, is introduced between the said nut and the templet in such a manner that when the spindle g is turned to lift the pin p, the templet 1s drawn tightly against the under plate e of the head.

It is to be understood that when a machine diflerent diameters, templets of varying size may be employed for holding the spindles either farther away from, or nearer to, the center of the head than shown.

Although I have described the use of a templet 0 for adjusting the position of the spindles 2', 11 it is to be understood that any ,other means suitable for the purpose may be employed.

s is the saddle adjustable upon the standard a and carrying the spindle t to which the grinding table'is fixed in a well known manner. u upon it for protecting the standard from the abrasive powder used in the grinding operation, the lower part of the said shield being composed of sections whichtelescope one into the other,

Claims.

1. In a lens grinding and polishing ma.-

As shown, this saddle has a shield I chine, the combination with a vertical pillar or standard and a fixed horizontally disposed head' secured to the upper end of the said standard, of a work support adjustahly mounted on the said pillar or standard, a

rotatable table mounted on the said support,-

a plurality of rotatable grinding 'tool operatmg spindles mounted in said head and means for simultaneously rotatingsaid spindle-S'. v i

2. In a lens grinding and polishing machine, the combination with a fixed horizontally disposed head, of a rotatable work support located below the same, a plurality of rotatable grinding tool operating spindles tally disposed head, of a rotatable work support located below said head, aplurality of vertically disposed rotatable tool operating spindles mounted in said head, means for adjusting each of said spindles substantially radially with respect to the work support and means for driving said spindles.

4. In a lens grinding and polishing ma.-

chine the combination with afixed horizon tally disposed head of a plurality o f'pivoted arms adapted to swing laterally in said head, a tool operating spindle carried by each of said swinging arms, means'for positively operating the several spindles independently, a rotating work supporting table and m eans for securing the said arms and spindles uniformly around the axis of the said work support;

, 5. In a lens grinding, and polishing machine, the combination w th afixed llOllzontally disposed head, or a rotatable Work support located below said head, a laterally swinging arm pii'otally mounted in i i ad, a tool operating spindle carried by said swinging arm, said head being pro disposed head, of a rotatable Work support located below the said head, a laterally swinging arm pivotally mounted in said head and provided adjacent to its outerend witlibearing portions, a vertically dispose-d rotatable spindle carried in said bearing portions, said head being provided with a curved slot for the passage of'the spindle and the adjacent bearing portion therethrough, and a securing device engaging said bearing portion of the arm forholding said arm and spindle in fixed relation with the work support. v

7. In a lens grinding and polishing machine, the combination with a horizontally disposed head, of a rotatable work support located below said head, a laterallvswingarin pivotally mounted in said liead,'a spindle mounted in said arm adjacent to the outer end thereof, means for securing said sprindle in fixed relation with said work support, said spindle and Work sup-v inn it toward the other.

8. Tue lens grinding and polishing machine, the combination with a horizontally disposed head, oi. a rotatable work support lcczited below the said head, of laterally si-inging' arm pivotally mounted in said head; a rotatable tool operating spindle mounted in said arm adjacent to the outer end thereof, a spring interposed between the spindle and a part coi'inected *ith said arm for pressing the spindle longitudinally toward the work support and QlQTiCGF: for holding said arm and spindle in fixed relation with the work support.

In a lens grinding and polishing machine, the combination with a horizontally disposed fixed head, of a rotatable work support located below said head, a laterally swinuing arm pivotally mounted in said head and provided with bearing portions adjacentto its outer end, a tool operating spindle mounted in said bearingportions and provided with a collar, a coiled spring encircling said spindle and interposed between said collar and a portion of said arm, and devices for holding said arm in fixed relation with said work support.

10. In a lens grinding and polishing machine, the combination with a fixed horizontally disposed head, oi a rotatable work-sup port located below these-inc, a pluralityot- 11. a lens grinding and polishin chine, the combination with a'fixed horizon tally disposed head, of a rotatable -Work supportlocated below. the same, aplurality of swinging arms mounted-1n said head,

laterally movable tool operating. spindlesmovably mounted-in said head anda (ls- 5, Y tachaole toinplet for holdingsaid spindles in lined relation with the ork support.

mina

tool operating spindles, lHOllIltEfl one in:

each of said arms and movable in a substan tially radial direction with respect to the axis of the work support and a templet having portions toriengaging parts connected with said spindles for holding them in fixed relation with the work support and means for detachably securing'the said templet to.

the head.

12. In a lens grinding and polishing Inacmne, the combination with a fixed hor zontally. disposed head, of a rotatable Work support located below the same, a plurality of swinging arms mo'unted in said head, tool operatingspindles-mounted one in each ofable securing bolt for said templet mounted in said head and provided w th a collar for engaging the templet, and devices for operating said bolt.

13. in a lens grinding and polishing machine, the combination with a fixed horn zontallydisposed head, of a rotatable work support located below the same, a, plurality of swinging arms mounted in said head, tooloperatinn spindles,inounted one in each (if-said arms and movable in a substantially radial direction with respect to the axis of the work support and a templet having portions for engaging parts connected, with said spindlesior holding them in fixed relationwith the work support. a vertically movable locking bolt for said templet, a clamping collar on said bolt for engaging the teinplet and an adjustable part on said bolt for engaging said collar.

i. a lens grinding and polishing machine, the combination with a fixed horizontally disposed head; of a rotatable work support located below the samea plurality of swinging arms mounted in said head, tool operating spindles, mounted one in each ot said arms and movable in a substantially radial direction with respect to the axis of the work support and a teniplet having portions for engaging parts connected with said spindles for holding them in fixed relation with the work support. a Vertically movable securing bolt mounted in head and provided with an enlarged part atits lower end, said templet having an aperture to accommodate said enlarged part, a detachable collar adapted to be inserted between the said enlarged part and the templet and means for moving said bolt longitudinally.

15.- In a lens grinding and polishing machine, the combination with a fixed horizont'ally disposed head, of a rotatable work support located below said head, a laterally swinging arm pivotally mounted in said head, a tool operating spindle carried by 7 machine, the combination with a fixed head.

saidswinging arm, and means for securing said arm and spindle in fixed position with respect to the work support, a rotary drivin'g' part for said spindle and .a flexible shaft connecting said driving part with said and a work support located below the same, of a plurality of laterally movable tool operating spindles mounted in said head,

means for securing said spindles in fixed re-- lation with the work su port, said spindles being movable longitudinally with respect to the head, a depressing spring connected with each spindle, driving-mechanism and flexible connections from said spindles to the driving mechanism.

18. In a lens grinding and polishing machine, the'combination with the work support provided with a rotary work holder, of a fixed head located above the work support, a plurality of laterally swinging arms mounted in said head, a-tool operating spindle carried by each of said arms, means vfor securing said arms and spindles in fixed relation with the work support, said spindles bemg longitudinally movable in said arms, depressing springs carried one by each of said arms-and engaging the spindle harried thereby, driving mechanism for operating said spindles simultaneously and a flexible shaft from each of said spindles to the said driving mechanism.

19, In a lens grinding and polishing machine, the combination with a vertically disposed pillar, a fixed head supported thereby at one side of the pillar, and comprising parallel horizontal plates, horizon tally swinging arms pivotally mounted between said plates, a spindle mounted in bearings adjacent to the outer end of each arm, and provided with a collar, a spring surrounding each of said spindles and interposed between the said oollar and a portion 'otthe arm, the lower of said horizontal plates of the head being provided with curved slots for the passage of said, spindles, and the adjacent portions of their bearings, a removable .templet provided with hook shaped portions engaging the spindle bearings','t,o hold the spindles in a prede termined relative position with respect to the work, a vertically in vable locking bolt for securing the templet in position passing vertically through the horizontal plates of the head and provided at its lower end with an. adjustable device, a locking spindle provided with an eccentric portion engaging said bolt, the templet being provided with an aperture for the passage of the bolt, a detachable slotted collar for engaging the said bolt above the adjustable device there on, a work support secured to the pillar and.

adjustable vertically thereon, and a' rotary work holding spindle carried by said work support, a vertical driving shaft carried by said pillar, and" driving pinion secured thereto, a plurality of pinions in engagement with said driving pinion'and curved flexible shatts connecting each of the tool spindles with one of said pinions. v

NIALCOLM BENTZQN.

\Vitnesse's:

C. G'. REDFERN, A.' AL TT. 

